Blood pressure independent effects of nitrendipine on cardiac structure in patients after renal transplantation.

Left ventricular hypertrophy is well established as a blood pressure independent cardiovascular risk factor in patients on renal replacement therapy. The effects of antihypertensive treatment on myocardial structure and function in renal transplant recipients have been so far only rarely investigated. In a double-blind, placebo-controlled study patients were randomized to the calcium channel blocker nitrendipine or placebo if the transplanted kidney had developed a stable phase. Normotensive patients received nitrendipine 2 x 5 mg daily or placebo, hypertensive patients received 2 x 10 mg up to 2 x 20 mg nitrendipine daily or placebo. To achieve adequate blood pressure control, all patients with still elevated blood pressure on study medication received antihypertensive drugs other than calcium channels blockers. Ambulatory blood pressure recording and 2D-guided M-mode echocardiography were performed at baseline and upon completion of the study. In addition, laboratory workup (including serum creatinine and lipids) was done, and serum aldosterone, plasma renin activity, plasma angiotensin II and blood glucose levels were measured in all patients at baseline and after at least 12 months of therapy. Ambulatory blood pressure was almost identical between both groups at study baseline and follow-up. In renal transplant patients on nitrendipine, posterior wall thickness (-0.10 +/- 1.77 mm) and septal wall thickness (-0.83 +/- 2.23 mm) did not change significantly from baseline. In contrast, posterior wall thickness (0.71 +/- 0.92 mm, P < 0.01) and septal wall thickness (0.97 +/- 2.20 mm, P < 0.05) increased in patients on placebo, which differed from the observed changes on nitrendipine (ANOVA: P = 0.093 and P = 0.048, respectively). Relative wall thickness, a parameter for concentric left ventricular hypertrophy, became numerically smaller on nitrendipine therapy from 0.46 +/- 0.07 to 0.44 +/- 0.09 (-0.02 +/- 0.09, NS) but increased from 0.42 +/- 0.08 to 0.48 +/- 0.08 in the placebo arm (+0.04 +/- 0.08, P < 0.02), which was also significant between the two groups (ANOVA: P = 0.036). Endocrine parameters, lipids and blood glucose were not different between the two groups. We conclude from these data that the calcium channel blocker nitrendipine exerted beneficial effects on cardiac structure in patients after renal transplantation independent of blood pressure.

[Decreased blood pressure in sleep and left ventricular hypertrophy in patients with kidney transplants]. / Blutdruckabfall im Schlaf und linksventrikuläre Hypertrophie bei nierentransplantierten Patienten.

Since left-ventricular hypertrophy (LVH) has been identified as a poor prognostic indicator in patients with secondary hypertension, we investigated 38 renal transplant recipients on antihypertensive medication with 24-h ambulatory blood-pressure measurement (SpaceLabs 90207) and determined their left-ventricular mass by two-dimensional guided M-mode echocardiography. An increased left-ventricular mass correlated with a reduced fall of diastolic blood pressure during sleep (r = 0.29; p less than 0.05), as well as with a reduced fall of mean arterial pressure during sleep (r = 0.31; p less than 0.05). Therefore, a less pronounced afterload during sleep is related to more severe left-ventricular hypertrophy, suggesting a worse cardiovascular prognosis.